Catamaran whit 2 Jet Ski pumps and 2 air cold diesel at 26 Hp?

Catamaran whit 2 Jet Ski pumps and 2 air cold diesel at 26 Hp?

Hi I’m having started to think how to build a trainable catamaran for easy handling.
Have start to think that I will use 2 air cold diesel engines’ at 26 hp connected to a jet ski pump each instead of ordinary propellers. Is it some big disadvantage to do so or any odder wrong thinking of me?

 

Disadvantage would be lower efficiency over a prop, especially at relatively low speeds and attaching two engines to a single jet pump sounds like a pain .
Outboards give more internal room and are a lot less difficult to install.

 

I figure a catamaran would have one engine and one pump in each hull.
How big is the thing? If you're talking about a six-metre, half-tonne runabout, you may be on to something interesting. But remember that a jet ski pump is tuned for high velocity and relatively low flow at very high RPM, when compared to a normal jet pump or a propeller. That translates to a significant loss of efficiency at lower power levels.

 

My planing was one engine and pump in ecth hull. And it could be around 5 meters long and 2.50 whith. A out bord enging is not a solution for me, have to be a fixt instalation what its well sound protekted.

 

just pull a couple of old jetskis apart and bed the engines/jets
into your cat, only engineering hasslre then is getting your jets steering right
sean

 

What diesels are you planning on using? They could be a bit heavy for a relative small boat.
How do you want to steer? Rudders or jet drives?

Regards

Alan

 

I had plan to youde KIPOR DIESEL 2 cylinder whit a wighit at 64 kg
The stering seams to be esyest whit the water jets.

 

I'm considering a similar setup for my sailing cat - using two 4-cyl petrol jetski motors instead of outboards. Only drawback is the reverse is not very strong, but then there is nothing the fishing line can tangle on

 

If you're considering diesel for fuel economy I guess it depends on how you want to use the cat. The 4 cyl motors has fuel injection etc and if you keep the revs down they do quite well on fuel.

 

If Im not wrong most jet ski´s have around 6500 rpm at max and the diesel 3400 rpm so I nead a gear box betwin to get the revs up. The quistion is then if the engine are strong enuf foor that task?